02 - 02
The EU was started to stop wars in Europe. After centuries of conflict, war between EU countries is now unthinkable.
Countries that left the Soviet Bloc have joined the EU and are doing well.
Leaving the EU could leave us out of justice, security and foreign policy cooperation with the EU. The UK for example has been a driving force behind EU sanctions against Iran and to a lesser extent, Russia. (Prospect magazine January 2016).
The peace process in Northern Ireland has benefited from the fact that both the UK and Ireland are members of the EU. If we left without a deal a hard border would be restored with all the risks of an outbreak of violence.